These are the dark days of December, as we approach Chanukah, Christmas and the Winter Solstice.
Most of the time, the daylight/nighttime hours change at the rate of around three minutes daily, but as we approach the Solstice, we inch forward and we measure the daily time difference in seconds. For example, on today, December 18, here in Butte, we have 8 hours, 38 minutes and 54 seconds from sunrise to sunset. Tomorrow we have 14 seconds less, and 9 seconds less on Friday.
The Winter Solstice happens at 9:19 p.m. on Saturday, December 21, and we’ll have 8 hours, 38 minutes and 26 seconds on both Saturday and Sunday. Over the following week, days will start growing longer, though at first the difference will still be measured in seconds.
The interesting part of the end of December is that while there is little difference in daylight hours, with the daylight on New Year’s Eve Day just four minutes more than on the Solstice, sunrise will be four minutes later on December 31 than on the 21st, but sunset will be 7 minutes later, and that later sunset seems significant.
Many calendars mark the date of the Solstice as the first day of winter. Scientists refer to that as the astronomical beginning of winter, with the Summer Solstice the beginning of summer, and the equinoxes marking the beginning of spring and autumn.
In reality, another standard, Northern Meteorological Seasons, makes more sense, as in that measurement, winter begins on December 1, spring begins March 1, summer begins June 1, and autumn begins on September 1.
When you consider a year such as 2019, when our first snowstorm of the season hit in late September, with almost unbelievable snowfall amounts on Montana’s Rocky Mountain Front, and Zero degree temps in early October, it seems kind of ridiculous to say that winter begins on December 21.
While the closing months of 2019 have seemed cold, we’d be mistaken to think that we’ve stopped climate change in its tracks. Consider the following information, as reported last week in the Washington Post.
In the arctic regions, climate change is truly alarming. In Greenland, home to a permanent ice sheet the size of Alaska, the ice is melting at an amazing rate. In the 1990s, Greenland lost around 33 billion tons of ice per year. Currently, the ice is melting at the rate of 254 billions of tons per year. Since 1992, Greenland has lost an estimated 4 trillion tons of ice. That volume of water is roughly equivalent to a global sea level rise of one centimeter. A centimeter is just less than half an inch, which may not sound like much, but a centimeter of sea level rise puts another 6 million people at risk for annual seasonal flooding.
At the current rate of melting, Greenland alone could contribute about 16 centimeters, about 6 inches, of sea level rise by the end of the century.
Another indicator is the melting of permafrost in the arctic regions of the world, including Alaska, Canada, Siberia and Greenland. Permafrost holds large amounts of carbon in the frozen soil, and as it melts, the soil releases large amounts of greenhouse house gases in the form of carbon dioxide and methane. This, of course, complicates human efforts to reduce greenhouse gases to combat climate change.
In fact, 2019 is shaping up to be the hottest year ever in Alaska. If you were standing on the shoreline of the Arctic Ocean at Nome, Alaska, last week, you would not be able to see any sea ice, which is highly unusual.
I’ll note that these reports don’t even mention ice pack losses in Antarctica.
Continuing on this note, last week, Time magazine named Swedish teenager and climate activist Greta Thunberg as 2019’s Person of the Year. I suspect that some will disagree and even be angered by the selection, but I look at it as a sign of hope that more people will take the issue of climate change more seriously in coming years.